721799717 has 2 divisors, whose sum is σ = 721799718. Its totient is φ = 721799716.

The previous prime is 721799713. The next prime is 721799723. The reversal of 721799717 is 717997127.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 632572801 + 89226916 = 25151^2 + 9446^2 .

It is a cyclic number.

It is not a de Polignac number, because 721799717 - 2² = 721799713 is a prime.

It is a super-2 number, since 2×721799717² = 1041989662922560178, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (721799713) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360899858 + 360899859.

It is an arithmetic number, because the mean of its divisors is an integer number (360899859).

Almost surely, 2^721799717 is an apocalyptic number.

It is an amenable number.

721799717 is a deficient number, since it is larger than the sum of its proper divisors (1).

721799717 is an equidigital number, since it uses as much as digits as its factorization.

721799717 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 388962, while the sum is 50.

The square root of 721799717 is about 26866.3305458710. The cubic root of 721799717 is about 897.0271113141.

The spelling of 721799717 in words is "seven hundred twenty-one million, seven hundred ninety-nine thousand, seven hundred seventeen".